Guidance on the Control of Odour and Noise from ... - Defra

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Maintenance requirements Proprietors of commercial kitchens are under a duty to ensure that the ventilation system serving the respective premises are maintained and operated effectively. Good maintenance is a prerequisite for ensuring that a system complies with Best Practicable Means under statutory nuisance provision and will form a key element of any scheme designed to minimise harm to the amenity under planning regulation. Good maintenance is also required by the Food Hygiene Regulations [20] and will minimise the risk of fire. 4.11.1 Consequence Of Poor Maintenance Poor maintenance is widely found with control systems. The consequence of poor maintenance is illustrated in the following examples. Example 1 Time Frame Performance of System System Pressure Drop New installed or maintained filtration system. Period 1 – continued operation. Period 2 – continued operation. Period 3 – continued operation and equipment failure. Example 2 Good flow, optimal grease and odour removal. Flow restriction introduced as fine filtration system becomes blinded with particulate matter. Flow restriction increases, resulting in the velocity through the system decreasing. This causes increased residence time within filters and improved control. This also causes the face velocity at the canopy to decrease. Eventually blinding of fine filters occurs and adsorption in carbon filter reaches maximum capacity. At this point the system fails completely and grease/odour removal will be negligible. Time Frame Performance of System New installed or maintained ESP. Optimal particulate removal. 76 Low pressure drop as per design. Increased pressure drop. Further increase in pressure drop. Further increase in pressure drop until flow within duct work drops. Period 1 – continued operation. Coating of charged plates resulting in reduced particulate removal efficiency. Period 2 – continued operation and equipment failure. Coating of internal surfaces continues until particulate removal efficiency drops significantly. Other maintenance issues such as shorting of electrical equipment will occur. Both examples of poor maintenance described above are commonly found in commercial kitchens. The resultant loss in performance is often put down to inappropriate equipment or design. It is however more likely that the main
contributory factor in poor performance of grease and odour removal systems is the inadequacy of the maintenance schedule applied to equipment. The optimum maintenance period will depend on the capacity of the equipment installed. It is fair to say that most kitchen ventilation systems are designed with very little excess capacity. A key consideration in the performance of the kitchen ventilation system is the buildup of debris within the ductwork itself. Good hygiene practice should ensure that the face of the canopy, filters and any other parts requiring cleaning are cleaned regularly to comply with the Food Safety (General Food Hygiene) Regulations 1995 [20] . It is unlikely however that such cleaning will be afforded to the ductwork beyond the canopy and coarse grease filtration system. Material adhering to any other internal surfaces within the duct will contribute to the overall odour emission from the premises. This feature is common with poorly maintained ventilation systems of any kind and will lead to increased and unnecessary loading on any arrestment equipment and can lead to corrosion of the ductwork itself. In extreme circumstances excess debris within a duct work system can be seen as grease and dirt accumulations around seals and joints in the ductwork. This debris is combustible are therefore is a potential fire hazard. Poor maintenance of ventilation systems can also lead to noise complaints. These are often attributed to worn bearings, imbalance due to erosion or damage, dust and deposits on the impeller and in the adjacent ductwork. Additionally, silencers may be damaged, eroded, corroded or clogged and flexible connectors may become brittle or stiff. 4.11.2 Recommendations for maintenance Maintenance of the kitchen equipment should be carried out in order to ensure the system remains as efficient as possible and also to ensure that the ventilation plant remains in good condition. Minimum performance requirements of general maintenance of a kitchen ventilation system [22] The ideal criteria for the debris accumulation within a ventilation system are as follows: Extract Surface Contaminant Limits Test Method 6g/m 2 180 µm Recirculation 1g/m 2 Supply 60 µm 1g/m 2 60 µm 77 Dust Vacuum Test (VT) Deposit thickness test (DTT) Dust Vacuum Test (VT) Deposit thickness test (DTT) Dust Vacuum Test (VT) Deposit thickness test (DTT) The maximum allowable debris accumulation within a ventilation system are as follows: Wet Film Thickness Test Measurement Recommended Action 200µm as a mean across the system Complete cleaning required Any single measurement above 500µm Urgent local cleaning required
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Guidance on the Co
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Report Guide 3
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4.4 Dampers 47 4.5 Fans 48 4.6 Acce
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canopy and entrained solid particle
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Executive summary Best practice for
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housing the commercial kitchen. Add
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1 Introduction 1.1 Preamble Problem
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2 Background 2.1 Odour 2.1.1 Odour
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2.1.5 Physical properties and odour
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Table 2.3 Moisture and grease/smoke
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L tot = 10log 10 ⎛ ⎜ 10 ⎝ L1
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Table 2.5 Sources of noise from com
Page 25 and 26: Area Effect UV/ozone systems Limite
Page 27 and 28: Odour have been set so that statuto
Page 29 and 30: Table 3.2 Summary of the roles of L
Page 31 and 32: British Standards, and guidance fro
Page 33 and 34: � Health and Safety legislation/g
Page 35 and 36: 4 Review of common types of kitchen
Page 37 and 38: Figure 4.1 Schematic diagram of a t
Page 39 and 40: More detailed description and input
Page 41 and 42: 4.2.4 Hoods/extract points A range
Page 43 and 44: to be increased where high output e
Page 45 and 46: Two types of system are available:
Page 47 and 48: duct penetrates the kitchen fire co
Page 49 and 50: Table 4.2 Advantages and disadvanta
Page 51 and 52: Table 4.3 - Noise characteristics o
Page 53 and 54: *manufacturer’s data. Mesh or imp
Page 55 and 56: • Disposable pleated filter actin
Page 57 and 58: • A temperature of 40 o C is cons
Page 59 and 60: 4.7.6 In-line oxidation systems Oxi
Page 61 and 62: • The height of external ground l
Page 63 and 64: 4.7.9 Summary of grease and odour m
Page 65 and 66: walls. (g) Noise radiated to outsid
Page 67 and 68: Figure 4.6 Dissipative duct attenua
Page 69 and 70: • general situation treated using
Page 71 and 72: 4.5 Panel and Bag £5,000 £335 £3
Page 73 and 74: Panel, Bag, HEPA and CF High to ver
Page 75: 4.11 Installation The following qua
Page 79 and 80: Table 5.1: Examples of wet cleaning
Page 81 and 82: 6 Acknowledgement Netcen would like
Page 83 and 84: 18) Noise at Work Regulations, Stat
Page 85 and 86: Annex A Summary of odour and noise
Page 87 and 88: Urban Kebab none At eaves height bu
Page 89 and 90: Metropolitan General advice 1 m abo
Page 91 and 92: • dimensions; • route; and •
Page 93 and 94: • volume of the kitchen; and •
Page 95 and 96: Annex C: Risk Assessment for Odour
Page 97 and 98: Annex D: Factors to take into accou
Page 99: Determine background noise at the a
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